This invention relates to a new and improved two level flush valve assembly for use in the water tank of a conventional toilet.
It has become more and more apparent in recent years that our nation's water resources are not as plentiful as they were once believed to be. Systematic efforts to conserve water are essential for the general welfare of our nation and its inhabitants. In this regard, it is well known that the conventional toilet consumes large volumes of water for flushing operations. Yet, only relatively small volumes of water are actually required for the most frequently occurring flushing operations, i.e. those which dispose of liquid wastes only. Accordingly, it is desirable to have an efficient means for partially flushing a conventional toilet to dispose of liquid wastes and totally flushing the same toilet to dispose of solid wastes.
Various means, including two level flush valve assemblies, for selectively partially and totally flushing a conventional toilet are well known in the art. Various two level flush valve assemblies, several of which are structurally similar to the present invention, are disclosed in U.S. Pat. Nos. 4,003,097; 4,042,982; 4,056,856; 4,096,591; 4,110,850; 4,172,299; and 4,173,801. Unfortunately, the two level flush valve assemblies disclosed in these patents have relatively complex operative mechanisms and are relatively expensive to manufacture. Most are difficult to install in the water tank of a conventional toilet. Many are so difficult to install that the services of a professional plumber would be required by the majority of homeowners desiring installation.
It would be advantageous to have a two level flush valve assembly having a simple operative mechanism which is suitable for use with the existing flush handle and lever arm of a conventional toilet. Preferably, such a flush valve assembly should be inexpensive to manufacture and easy to install. It is believed that a two level flush valve assembly having such advantageous features would be an efficient means for partially flushing the toilet when it is necessary to dispose of liquid wastes and totally flushing the toilet when it is necessary to dispose of solid wastes. And, of course, if a substantial number of homeowners accept and use such a flush valve assembly, the end result would be a substantial conservation of our nation's increasingly scarce water resources.